IEEE 802.16e ¡]also known as Mobile WiMAX¡^ is currently the international MAC ¡]medium access control¡^ standard for wireless metropolitan area networks. To enhance the network throughput and extend the coverage of base station, IEEE then defined the 802.16j standard. Clearly, one of the popular applications for WiMAX is the multicast service. On the other hand, the design of power saving technologies is important since mobile stations are often powered by batteries. In this thesis, we study the maximum energy-efficient multicast scheduling ¡]MEMS¡^ problem for an IEEE 802.16j network with transparent mode. Specifically, the base station should determine how to schedule the multicast data in a multicast superframe such that the multicast energy efficiency of network is maximal. We first prove that the MEMS problem is NP-complete. Then on the basis of SMBC-AMC, we propose its variant, called SMBC-relay, to solve this problem. However, in SMBC-relay, the base station may send the same multicast data several times, wasting the scarce bandwidth. Hence we we propose a genetic algorithm-based multicast scheduling algorithm, called GAMS. One of the key features of GAMS is that the base station can control when to terminate the algorithm by stopping the evolution at any time. Simulation results show that GAMS significantly outperforms SMBC-relay in terms of multicast energy efficiency.

The integration of cogeneration technologies in residential communities has the potential of reducing energy demand and harmful emissions. This study investigated the impact of selected design parameters on the environmental and economic performances of cogeneration systems integrated into residential communities in cold U.S. climates following a centralized or a decentralized integration approach. Parameters investigated include: 1) density, 2) use mix, 3) street configuration, 4) housing typology, 5) envelope and building systems' efficiencies, 6) renewable energy utilization, 7) cogeneration system type, 8) size, and 9) operation strategy. Based on this, combinations of design characteristics achieving an optimum system performance were identified. The study followed a two-phased mixed research model: first, studies of residential community design and three case studies of sustainable residential communities were analyzed to identify key design parameters; subsequently, simulation tools were utilized to assess the impact of each parameter on cogeneration system performance and to optimize the community design to improve that performance. Assessment procedures included: developing a base-line model representing typical design characteristics of U.S. residential communities; assessing the system performance within this model, for each integration approach, using three performance indicators: reduction in primary energy use, reduction in CO2 emissions; and internal rate of return; assessing the impact of each parameter on the system performance through developing 46 design variations of the base-line model representing changes in these parameters and calculating the three indicators for each variation; using a multi-attribute decision analysis methodology to evaluate the relative impact of each parameter on the system performance; and finally, developing two design optimization scenarios for each integration approach. Results show that, through design optimization, existing cogeneration technologies can be economically feasible and cause reductions of up to 18% in primary energy use and up to 42% in CO2 emissions, with the centralized approach offering a higher potential for performance improvements. A significant correlation also existed between design characteristics identified as favorable for cogeneration system performance and those of sustainable residential communities. These include high densities, high mix of uses, interconnected street networks, and mixing of housing typologies. This indicates the higher potential for integrating cogeneration systems in sustainable residential communities.

This dissertation addresses the issues of climate change and depletion of non-renewable resources of energy and water, and aims at eliminating the use of non-renewable resources of energy and water for the building operation in single-family detached residences in the U.S. With this aim, this study investigated the feasibility of the off-grid, off-pipe design approach in six climate locations across the U.S. to achieve self-sufficiency in a house for building energy, indoor water use, and household wastewater and sewage disposal using only on-site available renewable resources. For the analysis, a 2,500 ft2, 2000/2001 International Energy Conservation Code standard reference house with typical building and usage characteristics was selected as the base case. The six U.S. climate locations included: Minneapolis, MN, Boulder, CO, Atlanta, GA, Houston, TX, Phoenix, AZ, and Los Angeles, CA. The renewable resources considered for this study included: solar radiation, wind, biomass for building energy needs; rainwater for indoor water use. In addition, the building site was considered for the disposal of household wastewater and sewage. The selected climate locations provided different scenarios in terms of base-case building energy needs and availability of renewable resources. Depending on these, energy and water efficiency measures were selected for reducing the building needs. For the reduced building needs, the sizing of systems for self-sufficiency was performed, including: solar thermal system for building’s space heating and water heating needs, photovoltaic and wind power systems for building’s electricity needs; rainwater harvesting system for indoor water needs; and septic system for the on-site disposal of household wastewater and sewage. In this manner, an integrated analysis procedure was developed for the analysis and design of off-grid, off-pipe homes, and was demonstrated for six U.S. climate locations. The results of the analysis indicated that achieving self-sufficiency for energy, water and sewage disposal was possible is all climates provided the systems for the collection and storage of renewable resources were large. On the other hand, the utilization of these systems was small for locations, where the year-to-year and seasonal variations in the weather conditions and availability of climate resources was large. For increased system utilization, minimization of the peak building needs, utilization of harvested energy for secondary purposes, and considering alternative systems for such applications are preferred.

Ad hoc networks are becoming an interesting research area, as they inher-ently support unique network applications for the wireless communications in a rug-ged environment, which requires rapid deployment and is difficult to be provided by an infrastructure network. Many issues need to be addressed for the ad hoc networks. In this dissertation, we propose an efficient distributed coordination function, a dynamic rate adaptation and fragmentation scheme, and a simultaneous frame transmission scheme on the media access control protocol to enhance the power conservation of mobile hosts and to im-prove the network throughput of an ad hoc network. Extensive simulations are studied to evaluate the improvement of the proposed schemes. The results of the simulations exhibit significant improvement to the stan-dard access control protocol. Not only the improvement of the throughput of the ad hoc networks, but also the conservation of the battery power of the mobile hosts were achieved with our schemes.

Recent advances in wireless communication and micro-electro-mechanical systems (MEMS) have led to the development of implementation of low-cost, low power, multifunctional sensor nodes. These sensor node are small in size and communicate untethered in short distances. The nodes in sensor networks have limited battery power and it is not feasible or possible to recharge or replace the batteries, therefore power consumption should be minimized so that overall network lifetime will be increased. In order to minimize power consumed during idle listening, some nodes, which can be considered redundant, can be put to sleep. In this thesis study, basic routing algorithms and duty cycle control algorithms for WSNs in the literature are studied. One of the duty cycle control algorithms, Role Alternating, Coverage Preserving, and Coordinated Sleep algorithm (RACP) is examined and simulated using the ns2 simulation environment. A novel duty cycle control algorithm, Sink Initiated Path Formation (SIPF) is proposed and compared to RACP in terms of sleep sensor ratio and time averaged coverage.

Development and enhancements in Information and Communication Technologies (ICTs) is following a high level trend promising many opportunities to the economy, environment and society. Utilizing ICTs to enable improvements in the field of energy efficiency is becoming a very hot topic across the globe in this context. In this study both the enabling role of the ICTs for ensuring energy efficiency and the carbon footprint of ICTs considering also the rebound effects was analyzed as a case study for Turkish consumer electronics sector. Desktop research and in depth interviews with representatives of the sector, aimed at assessing current situation and trends in the field, provided a basis for a qualitative analysis. In our assessment main focus was put on the enabling role of ICT in achieving energy efficiency gains and / thus, we intend to explore whether utilization of ICTs can help improving energy efficiency in consumer electronics sector in Turkey. Results of the analysis showed that there is a limited inclusion of ICT directly enabling energy efficiency in the sector. Moreover, there is a lack of awareness on the concept of ICT for energy efficiency concept in the sector. Discussion of the results was followed by policy recommendations for the enabling role of ICTs for achieving energy efficiency targets in Turkey. We argue that, by increasing the awareness on the topics, utilizing the potential strength of R&amp / D capacities of the firms and deployment of links between the sector and global context on the ICT for energy efficiency, ICT can help improving energy efficiency in Turkish consumer electronics sector.

The Government of India has an ambitious mission of ¡¥power for all by 2012¡¦. This mission would require that the installed generation capacity should be at least 200,000 MW by 2012 from the present level of 114,000 MW. To be able to deliver this power to the entire nation, an expansion of the regional transmission grid-network and inter regional capacity to transmit power would be essential. The latter is required because resources are unevenly distributed in the country and power needs to be transmitted through great distances to areas where load centres exist. Indian government¡¦s ambitious plan can be met. Power generation is one thing but distribution and last mile delivery is a real challenge in remote rural India. 70% of India still lives in such rural settings. India is also notorious for loss of power in distribution due to its out dated distribution infrastructure and mismanagement. A lot is being done to improve the situation however to fast remedy the problem; government and private players can play an important role in setting up small power plants that are based on eco-friendly and efficient mode of power generation. India¡¦s western states and North eastern states are rich in natural gas. Unfortunately these areas are also remote, especially the North Eastern sector. Delivering power is quite a challenge. In search for a solution to this challenge we could be wise to choose greener solutions than otherwise. In the quest of which solution would be suitable for the chosen project, one could look across an array of available conventional and non-conventional sources of energy. Utilizing the locally available natural gas would be a right strategy. It also suits as a green choice. To exploit the availability of natural gas we would need technologies that are of right scale and are easily executable. A multi-million dollar mega gas power generation plant is neither plausible nor executable in those rural settings; however something of a smaller scale could be a good fit. There we see an opportunity for a green technology that may work wonder. Taiwan based Green Power Engineering Corporation has a solution in the form of their cutting edge gas turbine generator. With ease of setup and efficiency coupled with eco-friendly technology, the Gas turbine generators has the potential to be the solution to the much needed rural development by providing them continuous power.

The energy efficiency issue, which is subjected to an energy constraint, is important for the applications in wireless sensor network. For the distributed detection problem considered in this thesis, the sensor makes a local decision based on its observation and transmits a one-bit message to the fusion center. We consider the local sensors employing a censoring scheme, where the sensors are silent and transmit nothing to fusion center if their observations are not very informative. The goal of this thesis is to achieve an energy efficiency design when the distributed detection employs the censoring scheme. Simulation results show that we can have the same error probabilities of decision fusion while conserving more energy simultaneously as compared with the detection without using censoring schemes. In this thesis, we also demonstrate that the error probability of decision fusion is a convex function of the censoring probability.

This paper seeks to develop a framework for the successful implementation of energy retrofit projects in all settings, including those with the non-traditional structure and unique needs of some non-profit organizations. This will be accomplished using researched strategies for overcoming commonly associated challenges along with experiences gained through a real-life case study involving a multi-facility retrofit project in Atlanta's largest public park, Chastain Park. The framework includes the application of research based solutions for common challenges as well as specific strategies for the translation of collected data into an actual scope of work, methods for the collection of bids and selection of contractor(s), the importance of and methods for communicating amongst stakeholders, and the need for a dedicated project manager on site at all times.

<p> </p><p> </p><p>According to the Environmental Kuznets Curve (EKC), economic growth will eventually cause carbon dioxide emissions to decrease. Is this the case in Sweden? A time series covering the period 1800-1995 is used to analyze the relation between carbon dioxide emissions and income per capita in Sweden. The empirical results indicate that an EKC for carbon dioxide is highly likely to exist in Sweden for the examined period. To take the analysis further, a cross-section data set is employed to examine the relationship between carbon dioxide emissions, income per capita and 4 other potentially influential variables in 75 countries. Only carbon intensity of energy is significant for carbon dioxide emissions. This implies that the utilized energy source is of importance, and it is crucial to separate energy consumption from carbon dioxide emissions. Emissions is a matter of structural aspects such as the type of industry and production a country comprise, and what type of energy that is consumed; not merely the quantity of energy. Sweden has experienced a shift in production techniques and in energy supply, and the energy-efficiency has improved during the past 100 years. It is consequently plausible to believe that it is not a critical income per capita which decreases CO</p><p>2  emissions – it is the “right” energy sources, energy efficiency and improved technology.</p><p> </p><p> </p>